Effects Of Pyrethrion Insecticides On Mitochondria Menbrane And GSTs In Aphis Sp

Aphis sp. is one of the key pest of the wolfberry, and affect the production and quality of wolfberry in long-term.Chemical control is one of the main method of prevention and treatment, and pyrethroid insceticides have been used to control Aphis sp. The wolfberry is mainly distributed in the west of China, and it is a small economic crop in the area. Research about wolfberry is superficial..In this paper,the toxicity of insecticides was determined, and the effects of pyrethroid insecticides on mitochondrial ATPase, fluidity of mitochondrial membranes and glutathione S-transferaes (GSTs) in Aphis sp. were investigated. Based on this,effect of temperature on toxicological mechanisms of pyrethroids was studied.The main results of the paper were as follows.Residual film method was used to determine the toxicities of eleven insecticides. The results indicated that Aphis sp. showed the highest sensitivity to cyhalothrin, with LC50 value of 4.279mg/L, while the LC50 value of fenpropathrin was 184.84 mg/L and cyhalothrin was 42.98 times as big as fenpropathrin, The order of toxicities to Aphis sp. wascyhalothrin>bifenthrin>phenvalerate>cyfluthrin>imidacloprid>triazophos> permethrin>deltamethrin>beta-cypermethrin> omethoate> fenpropathrin.The effects of seven pyrethroid insecticides on two types of ATPase in Aphis sp.were investigated. The activity of two kinds of ATPase in Aphis sp. could be significantly inhibited by the seven insecticides. The inhibition of bifenthrin to Na+-K+-ATPase and Ca2+-Mg2+-ATPase was higher, the maxmal inhibition rate is 52.3% and 46.3%, respectively.The order of inhibition to Na+-K+-ATPase was bifenthrin>beta-cypermethrin>deltamethrin>permethrin>cyfluthrin>phenvalerate>fenpro pathrin in 1×10-4 mol/L.The inhibition rate of pyrethroids to Ca2+-Mg2+-ATPase was deltamethrin(42.86%),phenvalerate(36%),permethrin(34.97%),beta-cypermethrin(33.06 %),fenpropathrin(32.78%),cyfluthrin(30.28%). In meanwhile, the inhibition was increased with the concentrations increased,The fluidity of mitochondrial membranes of Aphis sp. was determined by fluorescence polarization techniqu. The result showed DPH can combined with the mitochondrial membranes of Aphis sp, and the incubation time was 30minutes and temperature was,25℃. Effects of different pyrethroid insecticides on fluidity of mitochondrial membranes were studied.The fluidity were decreased by the tested pyrethroids.. Effect of deltamethrin to fludity of Aphis sp was the most pronounced pyrethroids.. Effect of deltamethrin to fludity of Aphis sp was the most pronounced among these pyrethroids, and compared with control, fluidity of mitochondrial membrane affected by deltamethrin.decreased by 1.28 times.GSTs (glutathione S-transferases)specific activities affected by pyrehthroids in vivo and vitro of Aphis sp. was determined. In vivo,beta-cypermethrin, bifenthrin, permethrin could inhibited the GSTs activity of Aphis sp.. The GSTs activity was inhibited after treated with beta-cypermethrin, and the maximum rate of inhibition was 85.02%. Other pyrethroid insecticides induced significantly the activity of GSTs, and the degree of inducing by phenvalerate was the highest. However, in vitro, the GSTs activity could be induced by deltamethrin, fenpropathrin and cyfluthrin when the concentration was 1×10-4mol/L, Permethrin and phenvalerate inhibited the activity of GSTs, the maxr.ial inhibition rate was 52.3%.The toxicty bioassay of three pyrethroid insecticides to Aphis sp. was masured at 17℃、27℃ and 37℃.The result showed that cyfluthrin and phenvalerate possessed a negative temperature coefficient, but deltamethrin displayed a positive temperature coefficient. At the three temperature, inhibition of three pyrethroid insecticides to two type ATPase all showed a negative temperature coefficient. The fluidity of mitochondrial of Aphis sp. were determined at the three temperature. Phenvalerate and deltamethrin displayed a negative temperature coefficient. In addition, the temperature influences the GSTs activity of Aphis sp.. GSTs (glutathione S- transferases)specific activities in vivo and vitro of Aphis sp. was maxmal at 37℃.